Field of the Invention and Related Art Statement
The present invention concerns a retainer used for an air bag and, more in particular, it relates to a retainer used for an air bag made of a specific material.
A steering portion of a vehicle such an automobile is provided with an air bag that expands to inflate when sensing impact shocks, deformations, etc. upon collision of the vehicle.
FIG. 2 is a schematic front elevational view partially in cross section of a structure for attaching an air bag, in which are shown an air bag containing cover 11 (module cover), an air bag 12, a mountain ring 13, a retainer 14 (base plate), an inflator 15 and a rivet 16. The retainer 14 was made by applying electrodeposition coating on a steel sheet (SAP H 45, SPCC, SPCH, etc.) and has a shape as shown in FIG. 3. The retainer made of a steel sheet in the prior art shown in FIG. 3 had a large specific gravity and involved the following problems.
(1) Since the retainer is heavy, attaching operation is not easy, so that productivity becomes poor. PA1 (2) Reduction of weight in the structure for attaching the air bag is hindered. PA1 (3) Since large vibrations are caused and inertia moment is large due to the reason (2) described above, steering performance of the steering wheel is poor. PA1 (A) Applying short fibers onto paper with resin coating. PA1 (B) Dispersing fibers into a solution of a resin dissolved in an organic solvent and then applying the solution onto paper. PA1 (C) Casting a resin into a molding die containing fibers. PA1 (D) Casting a mixture of fibers and a resin into a die.
In addition, the steel sheet retainer requires coating such as electrodeposition coating for preventing rust, which makes the production cost expensive. Furthermore, since the retainer is manufactured by pressing the steel sheet, it also involves a drawback of poor shape adaptibility such as for reinforcement by locally increasing the thickness.